The Sentinel SAS® toolkit library contains stand-alone programming tools written to standardize routine programming procedures. Each tool is a self-contained SAS macro that executes a very specific task. These tools are used in combination to facilitate development of the Sentinel Modular Programs and other programs designed to run on data that adhere to the Sentinel Common Data Model (SCDM). The Age Stratification tool creates an age group variable consisting of custom, user-specified groupings, with allowance for any mix of time units.